1. Technical Field
The present invention relates to a liquid ejection device for ejecting a liquid on an ejection medium that is supported by suction on a medium support unit.
2. Related Art
From the past, inkjet printers (hereafter referred to simply as “printers”) have been put to practical use as liquid ejection devices for ejecting ink as a liquid from a liquid ejection head onto paper (ejection medium) in a sheet form supported on a medium support unit, and forming an image containing text or graphics. Among this type of printer, there is a printer that performs so-called “borderless printing” which ejects ink from the liquid ejection head on the entire surface of the paper to form an image.
With a printer that performs this kind of “borderless printing,” for example as disclosed in Japanese Laid-Open Patent Application Publication No. 2011-189538, at a medium support unit, ink discarding grooves that accept ink discarded away from the paper end parts ejected from the liquid ejection head are provided at positions according to the width direction end parts that is orthogonal to the transport direction of the supported paper. Also, a plurality of recesses in which are formed suction holes which operate a suction force for suctioning the paper to the medium support unit are provided between the ink discarding grooves. Then, of the recesses provided on the medium support unit, the ink discarding grooves are provided in communication with adjacent recesses in the paper width direction. Therefore, the paper is supported on the medium support unit by being suctioned and adsorbed to both the recesses on which the suction force acts directly and the ink discarding grooves on which the suction force acts indirectly via the recesses.
However, as disclosed in the above mentioned publication, at the medium support unit, while the ink discarding grooves are formed with a large width dimension to be able to reliably accept ink, the recesses in which the suction holes are formed has the width dimension formed to be small to suppress bending (cockling) due to direct action by the suction force on the paper. As a result, with the conventional medium support unit, the recesses are formed with a width dimension formed to be smaller than the width dimension of the ink discarding grooves. By the recesses and the ink discarding grooves being formed in this way, the paper is suctioned on the medium support surface so that it is in a state for which bending deformation (cockling volume) is suppressed.